Delays and the time it takes for a message to be dispatched are reliant on many factors. Local network load, individual cell tower usage and back-end capacity such as the servers which the message goes through.

One also has to question what form of message the ANU will use. If they use just plain SMS, then anyone can send prank warnings. So they may use MMS, which would have an image or sound that could be used to verify the authenticity of the message. IF they were to use MMS, the we are no longer talking a few bytes (i think about 64byts for a full SMS), but a few kilobytes. That may not sound like a lot, but when you multiply it by 15,000… you have a massive influx of data on to the network.

The point I think though is not to get the message out to every single person, but rather to get the message out to a broad group, from whom others can hear the news. All you need are a few dozen people on campus, in Civic and around the CBD and the message will soon spread.

Why not put the question to the telcos? ANU should have done this themselves, but I’m guessing that they haven’t – because the answer most likely would be along the lines of “the mobile phone network is not designed as an emergency warning system”. SMS traffic is treated as low-priority, I wouldn’t be surprised to see delays of several hours if this was actually used.

There’s a reason that the cops and firies still use push to talk radios.